1. Field of Invention
The invention relates to a lamp module for a motor-vehicle headlamp having a light source exhibiting at least two light-emitting surfaces each of which emits a luminous flux that can be controlled individually.
2. Description of Related Art
A lamp module of this type is known from, for example, EP 2 306 074, and suitable for generating a glare-fee high beam for motor vehicles. A glare-free high beam is understood to be high-beam light distribution in which partial regions can be dimmed if there is someone located in these partial regions who could be blinded therefrom. This could be, for example, the driver of a preceding or oncoming vehicle. A lighting function of this type is referred to a “partial high beam.”
The invention serves to, in particular, provide a high beam of this type without the need for mechanically complex and expensive adjustment systems.
Projection systems axe known in this context, the light sources of which include a configuration of individually controllable light-emitting diodes. A configuration of this type shall be referred to in the following as a “matrix.” A headlamp that exhibits a configuration of this type is also referred to as a “matrix headlamp.”
With the known systems, an intermediate image lying within the headlamp is generated from the light-emitting surfaces of the light-emitting diodes using a primary lens, which is subsequently projected onto the street in front of the lamp by a secondary lens system exhibiting a projection lens, as the light distribution of the headlamp in its forward region. By switching light-emitting diodes “off,” partial, regions of the light distribution can be dimmed in a controlled manner. A system of this type is known from, for example, DE 2008 013 603.
With DE 10 2010 023 360, a glare-free high beam has been realized using an LED matrix (LED=light-emitting diode), in which the individual LEDs are separately disposed as “surface-mounted devices” (SMD-LEDS) (components separately disposed at a spacing from one another). The resulting separation of the light-emitting surfaces of the LEDs is rectified by a matrix of primary lenses, which generates an intermediate image from the separated light-emitting surfaces in the form of a coherently bright area. Due to the imprecisions in the positioning of the SMD-LEDs, unfavorable conditions for the generation of a good intermediate image exist, which primarily is to be distinguished by its homogeneity and sharply focused edges of its partial regions formed by individual LEDs.
Other problems arise with systems of this type in that the light-retracting secondary lenses inevitably generate undesired color fringes at “light/dark” borders. This, then, becomes critical when, in particular, it has not been determined on which side of the “light/dark” border the bright region is located because this can vary depending on the traffic situation. To prevent such color fringes with a matrix headlamp having a light-refracting projection lens, it is known from the aforementioned EP 2 306 074 A that achromatic lenses made of two lenses can be used, increasing the weight and costs for a headlamp.
With this background, an objective of the invention includes providing a lamp module for a motor-vehicle headlamp with which a glare-free high beam can be generated and that does not exhibit the aforementioned disadvantages (or exhibits any of them to only a slight degree). Reflectors are also a fundamental possibility, but they are accompanied by other problems.